Global Climate Models (GCMs) are important tools for studying how climate change will impact our world. If we keep emitting greenhouse gases at current rates, the Earth will get warmer, leading to bigger changes than we've seen in the past. GCMs help us understand these changes. This article reviews how GCMs work and how they are used to study climate change impacts. It also talks about the limitations of GCMs on smaller scales and different ways to make their predictions more detailed.